Sean Parker can add one more title to his résumé — executive producer. The Silicon Valley titan and Napster co-founder is an EP on the new immigration film “Documented,” written and directed by Pulitzer-winning journalist Jose Antonio Vargas. Parker has in the past invested in social political initiatives such as the app Votizen, and he is a founding member of Mark Zuckerberg’s immigration advocacy group FWD.us, which co-hosted a San Francisco screening of the doc this month.